Here are all of the options, I think, based on following these instructions in my car just now. Some are able to be modified, and some are just readouts.
Scared for now to change some of the settings.

Some I find curious, though -- Like the DVD Region setting does appear to be modifiable which I'm really surprised by.
Anyone see anything of particular interest?
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System Config
---- Batt. Voltage
---- Speed
---- Save to USB
---- Save to USB (Persisten…
---- Navi Test Mode
---- DMB Test Mode
---- Pos Tracking DBG
---- Print DBG Message
---- Print TimeStamp
---- Internal update
---- HDD CRC Check
---- Ramguard
---- Multicore Log
---- Slow Slide
---- FadeTime Test
---- Get HU Status
---- Sound Tuning Test
---- Gain Source (disabled)
---- Gain (disabled)
---- Navi Voice Gap (disabled)
---- Chime Volume (disabled)
---- DTMF Volume (disabled)
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Variant
---- Country
---- Vehicle
---- CCP
----
System Variant Settings
------- Navigation
------- MTS
------- SDS
------- RSE
------- DMB
------- MMU
------- XM Radio
------- HD Radio
------- Rear Camera
------- Front Camera
------- ECS Height
------- ECS Suspension
------- US Unit
------- AQS
------- Bluetooth
------- Steering Easy Ac.
------- Seat Easy Access
------- Door Lock Sound
------- Radio Region Code
------- Twice Unlock
------- PGS
------- CombiCluster
------- EQ Limo
------- LDWS_Belt
---- DVD Region Code
---- DVD Lang
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Diagnostics
---- Read Active DTCs
---- Read All DTCs
---- Delete DTC Groups
---- Reset System
---- Reset Component
---- Start XdB Test
---- Start Wake Up Line Test
---- Start RBD
---- Diag Component Status
---- Start Update from CD
---- Status of DVD slots
---- GIRO request
---- Get all Software Versions
---- Set delivery settings
---- Set MMI-Lang. to Eng.
---- Switch Fan on/off
---- Control Fan of UTA
---- Switch to DMB
---- Switch to CAM
---- Switch to MMU
---- Switch to MTS
---- Eject All Discs
---- Load Disc
---- Delete Nav.DB
---- HDD CRC Check
---- Learn WRC
---- MOST Reset (Light Off)
---- Delete Navi Persistence
---- Show Credits
---- Disable Pana FIX
---- Enable KTRace on WD_...
---- HD Switch
---- HD Status
---- HDBER
---- HD Performance
---- HD Blending
---- HD Calibration
---- HD Measurements Reset
---- HD Software Version
---- BERMeasurement ON/…
---- Start XMByPass
---- Signal Strength
---- Tuner Status
---- Lock Status
---- C/N Values
---- BER Percentages
---- Reed-Soloman Error Val…
---- AGC Values
---- Current NCO Status
---- SDEC Software Version
---- XM Stack Software Vers…
---- CBM Stack Software Ve…
---- XM Module Software V…
---- XM Module Hardware …
---- Clear XM Chipset NVM
---- XM CBM Module Debug…
---- TTS Test